Citrus Psyllid Wasp

Top close view of a tiny wasp with clear wings on a green background

Female Tamarixia radiata ectoparasitoid. Photo by Mike Lewis, FDACS-DPI.

Citrus greening disease, Huanglongbing (HLB), is transmitted by the Asian citrus psyllid. Since 1999 biological control wasps, Tamarixia radiata, have been released in commercial and research groves as a means of controlling populations of the Asian citrus psyllids. These beneficial insects are now available to home gardeners. The tiny wasps only attack the Asian citrus psyllid and make their attack on two fronts.

Female wasps lay eggs on the underside of Asian citrus psyllid nymphs. As the wasps grow and develop they feed off their Asian citrus psyllid hosts, which are left dead when the wasps emerge as adults. Additionally, adult female wasps feed directly on the Asian citrus psyllid nymphs. These two ways of attacking the Asian citrus psyllids means that these wasps control pest populations through parasitism and predation.

The Florida Department of Agriculture and Consumer Services Division of Plant Industry (FDACS-DPI) has developed a biological control program to release these wasps across Florida’s dooryard citrus plantings. Interested homeowners can sign up for the program at http://freshfromflorida.com/TRA or by calling the DPI Helpline at 1-888-397-1517.

There are some things to remember before releasing these parasitic wasps. Wasps should be released outside of any area of insecticidal spray. Additionally, wasps need to be released where psyllid nymphs are found since this is the only stage of the Asian citrus psyllid’s life cycle the wasps attack. Finally, ants need to be controlled in areas where the wasps are being released. This can be done by simply applying a 2 cm wide barrier of sticky Tangelfoot or other non-insecticidal barrier at the trunk of your citrus tree. This is an important step as the presence of ants can decrease the effectiveness of wasp biological control by 85 percent!

While these wasps will not completely eradicate the Asian citrus psyllid pests, they are an important part of minimizing the problems caused by the Asian citrus psyllid.

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